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Dear John,the samples you gave regarding Nullable are wrong , for example Console.Write(aVar.ToString()) ; You have not added the parentheses which why you always have an error , you can not use nullable string because its of reference type and you can console write a null integer which will be nothing on screen. please Sir , you need to give much care

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Last reply by: John SnapeThu Feb 4, 2016 12:12 AM

Post by Salman Khanon June 22, 2015

I have been struggling for almost 3-4 days with the concept of floating-point numbers. It involves really hard mathematics and we should also understand fixed-point numbers as well. it is very hard to do. I've been trying to go through different sources, like the book "Computer Organization and Architecture" by William Stallings. Why this topic was just touched so briefly upon? It is not so trivial and is very hard. P.S. i'm not that good in Mathematics, just finished A level high school.

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Last reply by: John SnapeThu Mar 26, 2015 10:52 AM

Post by Keith Lashleyon March 26, 2015

My Visual Studio claims that my projects were not loaded correctly when I try to open them. What is wrong? Can you help me please.

Declaring Variables

The standard variable declaration statement is:

[datatype] variable = [value];

Value types hold their data directly

Reference types only hold a pointer to the actual data somewhere else in memory

All built-in numeric types are value types

Use a data type with enough precision for the work you need to do

You have to give some value to a variable before you use it or you will get an error

Constants never change during the program execution

Constants can be any data type

Usually all uppercase so they are easily seen when scanning code

Implicit conversions are always allowed for widening conversions (where the source data type is less precise than the destination data type)

Explicit conversions are for narrowing conversions

Null means "never entered"

Use ? after the datatype in the declaration for nullable variables

Boolean is a "Yes or No"/"True or False" type variable

False always converts to/from zero

Although discouraged, you can use a reserved word for a variable name by always starting it with @